Quadratus Femoris : one of six Hip lateral rotators

Happy Muscle Monday! Another deep hip rotator! Today we're talkin' QUADRATUS FEMORIS, not to be confused with thigh muscle Rectus Femoris, (one of your Quads!)

 Quadratus Femoris stretches between your sits (butt) bone and femur (thight bone!)

Quadratus: refers to its 4-sided rectangular shape.

Femoris:  attaches to the femur bone



QUADRATUS FEMORIS  MUSCLE ATTACHMENT POINTS:
 

ORIGIN:  Lateral border of the ischial tuberosity

INSERTION:  Intertrochanteric crest of the femur (between the lesser & greater trochanters)

 

QUADRATUS FEMORIS MUSCLE ACTION:
 

Lateral Rotation of the Thigh at the Hip Joint 
It also assists in Adduction of the thigh at the hip joint

Lateral Rotation of the thigh at the hip joint (standing)

Thigh Adduction

 

saving the most popular hip rotator for last : PIRIFORMIS 

See you next week!

1 of 3 Hamstrings: SemiMembranosus

Last week we got into the Hamstrings! 

We started with SemiTendinosus and Today we're talking SemiMembranosus

(see how I've capitalized the T in SemiTendinosus -and the M in SemiMembranosus? I just wanted to note that that is something that I do to help me distinguish between the two ;)

  SemiMembranosus  also lives deeper than - and larger than - SemiTendinosus.

okay, now forget T  :

SemiMembranosus

SemiMembranosis muscle attachment points:

Origin: Ischial Tuberosity *

Insertion: Posterior surface of the medial condyle of the tibia

((approx behind and just below the knee joint))

 *did you know that all three hamstrings share the same origin of ischial tuberosity?

Ischial tuberosities aka "sits bones", you know those points of the pelvis, butt bones if you will? here's a visual:

  The tibia is a lower leg bone, the larger one that mid way down we refer to as our shin (bone)

This muscle also attaches to the medial meniscus of the knee ( a pad of cartilage wedge between your femur (thigh) bone and your tibia.  Medial Meniscus helps to reduce friction in the knee joint.

Here is a view of the back of the knee (aka Posterior view)

Posterior View of knee joint. 

not shown: Lateral menisus (also wedged between just on the outside (lateral) side of the knee joint.

The hamstring muscle bellies turn into skinny tendons that cross the knee.

Because they cross both joints, the muscle actions will happen at the hip AND the knee:

SemiMembranosus Muscle Actions:

same actions as last week's SemiT

When we're talkin' hamstrings, there are two main actions that come to mind:

- Extension of the thigh at the hip joint (aka coxal joint)

- Flexion of the leg at the knee joint (aka the tibio-femoral joint)

But wait there's more!

Apparently SemiMembranosus also assists in:

'posterior tilt' of the pelvis at the hip joints

(tucking your tailbone down)

medial rotation of leg at hip joint

(imagine standing on one leg and then turn the lifted ankle INwards)

But wait!

-WHEN the knee is flexed, it is said that medial rotation of the knee @ the t/b joint is possible 

(say whaaaat? sounds unfortable - I imagine it's just a micro movement -barely noticable)

Alsoooo...

Standing up and sitting down would be really difficult to do with our hamstrings!

Hamstrings can get tight from too much sitting :(

There are three hamstrings, located on the back of (posterior) thigh bone (thigh bone = femur).  

More specifically, they are tucked between Vastus Lateralis (quad group)

and Adductor Magnus (adductor group)

One more Ham to go!

Rectus Femoris - 1 of 4 Quads

I've been saving my favourite quadricep muscle for last! 

RECTUS FEMORIS (Rec Fem) is special because not only does it cross the knee joint (and extend the leg - like the other three quad muscles) but it also crosses the HIP Joint 

- help you to flex your hip.

Because of this, Rectus Femoris is part of the "Hip Flexor Group" - along with IlioPsoas  

Rectus Femoris is superficial - it lives on top of the other quads. However, portions of the Sartorius and TFL muscle cross on top of Rec Fem  (making them superficial to Rec Fem)

 Muscle Attachment Points:

Origin: Anterior Inferior Iliac Spine (AIIS)

Insertion: Tibial Tuberosity 

(same attachment point as the rest of the quads )

 

original image c/o studyblue.com

 

tibial tuberosity is just below the knee cap - on the tibia :)

Rectus Femoris Muscle Action(s):

a) extends the leg at the knee joint

b) flexes the thigh @ the hip (coxal) joint

(aka Hip Flexion)

a)

b)

 

And that's Rectus Femoris!

we're done the quads!

The other quads are: 

vastus intermedius

vastus medialis

vastus lateralis

and what do they all have in common? 

They all join together, turn into the patellar ligament/tendon - and insert into the same place - the tibial tuberosity ! And they help you kick stuff..

 

BYE!

TFL: Tensor Fasciae Latae

This little muscle (just three fingers wide!)  lives on the front of you hip - kindof where your front pocket would be.  Called TFL for short is one of two muscles that attach to the IT Band.  

Your IT Band (IlioTibial Band) is a thickening of the fascia (a long band of connective tissue) on the outside of your thigh. 

TFL Muscle Attachment points:

Origin:  Anterior Superior Iliac Crest (ASIS)*

Insertion: Iliotibial Band (ITB)**

*The ASIS is a bony bump on the front of your hip bone. Like if you were to put your hand on your hip your middle finger may end up touching the ASIS :)

** The ITBand is notoriously tight on everyone as it is put into a shortened state in the seated position. It starts on the Iliac crest (ASIS) crosses the hip joint AND the knee joint - attaching onto one of the lower leg bones - the Tibia. Now you see how it gets its name: Ilio-Tibial Band!  

A tight ITB and result in either hip and/or knee pain

TFL Muscle Actions:

 image c/o rehabforrunners.co.uk

Flexion of the thigh @the hip joint

Medial Rotation of the thigh @the hip joint

Abduction of the thigh @the hip joint

TFL in action!

Also did you know that TFL also stands for :